•Use power sizing tools to calculate the infrastructure required as configured and allow some flexibility for growth. HP provides power sizing tools for all its current industry standard servers. These calculators can be found at the following locations:
o For ML and DL products, on the HP website (http://h30099.www3.hp.com/configurator/powercalcs.asp)
o For BladeSystem products, on the HP website (http://www.hp.com/go/bladesystem/powercalculator)
These tools provide a conservative estimate of power loading values at a given system utilization as well as a theoretical maximum load that the system could achieve as configured. Use of these tools allows the infrastructure designer to use realistic maximum values to estimate power loading and circuit requirements. In this scenario, however, monitoring tools such as Insight Power Manager or HP Monitored PDUs must be used to ensure that the continuous loads do not exceed 80 percent of the rated circuit load.
•Install devices in a test environment and measure the actual worst case loads running the applications and loading that is specific to your environment, and then size the electrical infrastructure accordingly. This method is the most accurate, but may not be practical for many customers. This method would also require ongoing monitoring of the installation to ensure that infrastructure is not overloaded as applications and loads change.
•Manage the electrical load using several available HP BladeSystem features. A Dynamic Power Cap can be set at the enclosure level. The Onboard Administrator actively manages the blade power caps to ensure that the enclosure electrical load does not exceed the Dynamic Power Cap value while optimizing blade performance. HP Power Regulator can be set to Static Low to reduce power consumption, and together with Insight Power Manager can be used to provide
•Size air conditioning and UPS devices with typical ratings, but account for overloading that could take place with additional infrastructure growth.
HP recommends a cooling plan for the maximum rated power output of the room and a growth plan for cooling the infrastructure.
When determining power requirements, always consider any peripheral equipment that will be installed during initial installation or as a future upgrade. To determine the power required to support these devices, see the applicable documentation for such devices. HP recommends using dedicated breakers for peripheral equipment.
Electrical load requirements (circuit breaker sizing)
IMPORTANT: LAHJ is the final authority regarding adherence to
HP recommends derating the power distribution systems for one or both of the following reasons:
•To avoid nuisance tripping from load shifts or power transients, do not run circuit protection devices continuously above 80 percent of their RMS current ratings.
•Safety agencies derate most power connectors to 80 percent of their RMS current ratings.
Power requirements and considerations 31
